<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        function changeImg(){
            var imgObj = document.getElementById("codeImg");
            imgObj.src="/checkCode?"+Math.random();
        }
    </script>
</head>
<body>
    index界面
    <a href="/user/del/1">删除</a>

    <div>
        验证码：<img src="/checkCode" id="codeImg"><br>
        <a href="javascript:changeImg()">看不清楚，换一张</a>
    </div>
</body>
</html>